Acquit without blame a bishop found with crack (7)
I believe the answer is:
absolve
'acquit without blame' is the definition.
(absolve from blame)
'a bishop found with crack' is the wordplay.
'bishop' becomes 'B' (chess abbreviation).
'found with' says to put letters next to each other.
'crack' becomes 'solve' (crack can mean to solve or decipher).
'a'+'b'+'solve'='ABSOLVE'
(Other definitions for absolve that I've seen before include "Grant remission of sins" , "Exonerate" , "Fully pardon" , "Declare (someone) guilt-free" , "Set free from guilt" .)